mpsutil: Clean up libutil deps

mpsutil doesn't use libutil, so doesn't need to include libutil.h. See
commit 76103694a051335bec1da318f9c6e3a676dc0145.

No functional change intended.

MFC after: 1 week

(cherry picked from commit d56ce5915c41517ccc7de2510daec200e100ef68)